Modern pieces of furniture such as chairs, tables, step-ladders or ladders show, regardless of the material constituting the structural members of said pieces of furniture, pronounced idiophonic effects when bumped one against another or against stationary structures, as can be appreciated when setting up banquet or exhibition halls or where one is in schools, particularly in infant schools. By idiophonic effect what is meant is the intrinsic sound-giving or resonant character of solid structural members of pieces of furniture when bumped, an effect utilized and amplified, for instance, in wood tom-toms. For aesthetic and protective purposes, and also for facilitating their maintenance, modern pieces of furniture often comprised structural members which are at least partially externally coated by a sheathing which is obtained either by depositing an enamelled coating material thereon or by applying on the members a thin sheath of plastic material. The adjunction of such a thin sheath to the structural member to which it closely adheres does not modify the proper configuration of said structural member and reduces only by a very modest extent the drawbacks of the above-mentioned idiophonic effects.